[Spitz nevus and Reed nevus: simulating melanoma in adults].

One hundred and three cases of Spitz nevi were reviewed, 36% of these patients were adults. The lesions in children occurred primarily on the face and secondarily on the trunk followed by the extremities. In adults, they affect the legs in women, and the trunk in men as does malignant melanoma. Clinically they were diagnosed more frequently as Spitz nevi in children and adolescents than in adults. Spitz nevi were most commonly mistaken clinically for "common" melanocytic nevus, hemangioma, verruca, fibrous histiocytoma, molluscum contagiosum, granuloma pyogenicum, keloid, and melanoma. Histologically, there are various expressions of Spitz nevi, but they are usually compound melanocytic nevi with little pigmentation and typically large spindle- and/or epithelioid melanocytes. There are only small histopathological differences between Spitz nevi in childhood and adulthood: one important feature rarely seen in Spitz nevi of adults is multiple mitotic figures at the dermo-epidermal junction but rarely at the base of the melanocytic nevus. Nevus Reed is considered to possibly be a distinctly pigmented variant of Spitz nevus.